"Deserted cities of the heart" by Cream (Clapton on guitar of course)
"Free Bird" By Lynyrd Skynyrd (Collins on guitar)
"Sultans of Swing" LIVE from the Alchemy album by Dire Straits (Knopfler on guitar of course)...

But I nominate the underrated Davey Johnstone for the long fade dual guitar wank end of Jim Steinman's Stark Raving Love - https://www.youtube.com/watch?v=J18ihQmr0d0 - skip to 5:13 for the ending - Probably a tongue in check take on guitar workouts of the 70s - spot the Peter Gunn and All Along The Watchtower nods

and of course the guitar solo which never really happens - I am talking about Brian May at the end of We Will Rock You - you really want more and it never happens :(

and to risk the flames of people...the guitar synth (?) solo on Daft Punk's Digital Love

David Gilmour is one of the most overrated guitarists ever. Once you get past the "woah that's so awesome!" parts of Pink Floyd, you see it's mostly filler and barely adds anything innovative musically the table. Prog Rock in general suffers from this problem a lot, especially since it's basically white rockers imitating Jazz Fusion (another watered down substance of a great musical art form)

If you want some "best" guitar solos ever, go pick up a Hendrix album or a Jeff Beck album. You can start with Axis: Bold As Love and listen to the solos on Bold As Love, Little Wing, and Spanish Castle Magic. If that's not enough for you, go for the Woodstock LP and have your mind blown at some of the greatest soloing you could ever imagine hearing, since every Hendrix clone in the world has yet to totally master the techniques on that album.

With Jeff Beck, go with the Wired album and listen to it from start to finish. If that's not enough pick up Blow By Blow, most people are convinced that was his finest work. He even did some pretty nice solos with Stevie Wonder on some of his 70's records.

Funny I always see the usual names in these conversations; Van Halen, Gilmour, Clapton, Rhoads, but I never see Jeff Beck's name brought up. He's the only guitar player I can think of that came close to Hendrix's shadow and lived up to that image without being a rip off/clone of the man. Almost every British guitarist not named Eric Clapton, got their chops from Beck somewhere down the line. He's easily one of the most ripped off guitarists ever, and he don't get much credit it seems.